First Day of Fall?

In the Northern Hemisphere, the fall equinox marks the first day of fall (autumn) in what we call astronomical seasons. There's also another, more common definition of when the seasons start, namely meteorological definitions, which are based on average temperatures rather that astronomical events.

Autumnal Equinox – Southern Hemisphere

(Australia, New Zealand, South America, southern Africa)

March Equinox in Washington DC, District of Columbia, USA is onWednesday, March 20, 2019 at 5:59 pm EDT(Change city)